SPACE USE IN SOLITARY TAMARINS

Primate social groups form in response to the balance of costs and benefits around the act of dispersal. Theoretical work has illuminated the ecological and social forces that determine that balance, both in primates and in animals more generally, but the act of dispersal itself is less well understood. After an animal leaves its natal group, where does it go? How does its behavior change in the months and years between dispersal and immigration into a new group? Due to the inherent difficulty in locating and following dispersed individuals, and the necessarily small sample sizes involved, these questions are difficult to answer. Here we present the movements of two dispersed primates during the summer following their dispersal. One is a female emperor tamarin (Saguinus imperator) and the other a male saddleback tamarin (S. fuscicollis). Home ranges are based on 55 hours of track data (S. imperator) and 29 hours (S. fuscicollis), respectively. In addition, we present a series of sleep tree to sleep tree distances, which indicate total end-to-end travel distance for each species. The S. imperator female exhibited a larger home range and greater variability in sleep tree distances than conspecifics in established groups, including her natal group; the opposite was true for the S. fuscicollis male. These results suggest that dispersal strategies vary significantly in closely related species.